NADIS Bulletins: Feeding the Sow Around Farrowing
Uploaded April 2006
www.nadis.org.uk

Reports are regularly received from NADIS pig vets of milking problems in sows that arise as a result of faulty feeding. The whole issue of farrowing fever, MMA and udder congestion is frequently muddled but in the absence of primary infection in the udder, most of these problems can be traced back to the nutrition of the sow/gilt in the immediate pre-farrowing period. A number of distinct patterns can be identified:-

1) Excess feed intake pre-farrowing producing excessive milk that then congests the udder and leads to tissue damage.
2) Constipation often arising from a change from straw based dry sow accommodation to low fibre lactator at low levels, allowing endotoxins to be produced in the gut, which have a damaging effect on udder tissue.
3) Inadequate udder development in gilts.

Each requires explanation.

1) Excessive milk production.
The quantity of colostrum/milk needed by a litter of newborn pigs in the first 1-2 days of life – probably no more than 2 litres of milk per day. The modern sow is capable of producing much more milk than this. If fed high levels of high protein/high lysine diets (such as lactator diet), udder development can be rapid and excessive in the immediate period leading up to farrowing. The failure of the new born pigs to “milk out” the sow will lead to pressure build-up in the udder, which can be most easily felt at the side of the udder where the mammary gland meets the abdominal wall. It will feel hard and angular rather than soft and round. As this pressure builds up in the udder, the milk producing cells will be damaged and, at the mildest end of the scale, will fail to yield sufficient milk as demand increases. Individual glands may dry up completely and, in severe cases where the whole udder is affected, damaged tissue will release toxins, which may suppress appetite and raise body temperature.

In really extreme cases, fluid may accumulate at the rear of the udder (oedema) and such cases will often “dry up” completely.

The key to avoiding this problem is to reduce feed levels – particularly where entry to the farrowing house coincides with a change onto lactator ration – progressively over the 5 days prior to farrowing. In very general terms, reduce to maintenance levels on entry to the farrowing house with a further reduction to 1kg per day for sows 48 hours prior to farrowing. Following farrowing, the well established steady build up without a pre-set maximum should begin, taking care not to stall sows by too rapid an increase.

This dramatic fall in feed levels may coincide with a loss of fibre as sows come out of straw based accommodation and this lack of “gut fill” may lead to extreme agitation in some animals. This can be offset by either offering a handful of straw to pre-farrowed sows in the farrowing house or by use of bran as a gut filler.

2) Constipation and Endotoxin Release.
The loss of high fibre intake, particularly if combined with reduced feed levels can lead to a cessation of gut motility and ultimately constipation. The normal bacterial flora of the gut is in a state of continual turnover with dead bacteria flushed out in the faeces. If the gut becomes static, these bacteria form toxins which are absorbed and can lead to damage of the udder tissue and loss of milk production.

This can be simply avoided by ensuring that fibre intake is maintained either using straw or bran. It is important to ensure adequate water supply, particularly with bran which absorbs at least its own weight in water.

3) Gilt udder development.
In rare circumstances, udder development in gilts will not occur resulting in a failure of lactation at farrowing and consequent immediate starvation of the litter. Whilst there are a number of possible causes (such as mycotoxicosis) this problem is mostly seen when gilts are maintained up to the point of entry to the farrowing houses on very low protein/lysine dry sow diets. The low protein means there is no stimulus for tissue growth. In these circumstances, it may be necessary to switch gilts either onto lactator diet 2 weeks prior to farrowing or to use a specialist gilt rearer diet which tends to have a higher protein/lysine specification than dry sow diets. In either case, it is critical that over-feeding is avoided so that udder development is not excessive, as detailed in section 1 above.
 

Mark White BVSc DPM MRCVS
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